The polymerization of olefins is catalyzed by transition metal complexes of selected imines, amines or phosphines containing another group such as ester or amide, and in some instances other olefinic compounds such as unsaturated esters may be copolymerized with olefins. Useful transition metals include Ni, Fe, Ti and Zr. Certain types of late transition metal complexes are especially useful in making polymers containing polar comonomers.
The polymerization of olefins such as ethylene and propylene is a very important commercial activity, and such polymers in various forms are made in enormous quantities for very many uses. Various methods are known for polymerizing olefins, such as free radical polymerization of ethylene, and coordination polymerization using catalysts such as Ziegler-Natta-type and metallocene-type catalysts. Nevertheless, given the importance of polyolefins new catalysts are constantly being sought for such polymerizations, to lower the cost of production and/or make new, and hopefully improved, polymer structures. More recently so-called single site catalysts using late transition metal complexes have been developed, and they have proved in many instances to give different polymers than the earlier known early transition metal catalysts. See, for example, U.S. Pat. Nos. 5,714,556, 5,880,241 and 6,103,658 (all of which are incorporated by reference herein for all purposes as if fully set forth).
Another type of useful polyolefin is one that contains polar comonomers, such as acrylates. These copolymers are made especially well by a new type of complex in which a certain type of ligand is used.
This invention concerns new transition metal complexes, and processes for the polymerization of olefins using such new transition metal complexes.
A first aspect of the present invention concerns a Group 3 through 11 (IUPAC) transition metal or a lanthanide metal complex of a ligand of the formula (I) 
wherein:
Z is nitrogen or oxygen; and
Q is nitrogen or phosphorous;
provided that:
when Q is phosphorous and Z is nitrogen: R1 and R2 are each independently hydrocarbyl, silyl, or substituted hydrocarbyl having an ES of about xe2x88x920.90 or less; R3, R4, R5, and R6 are each independently hydrogen, hydrocarbyl, a functional group, or substituted hydrocarbyl; R7 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or silyl; and R8 is hydrocarbyl, substituted hydrocarbyl or silyl; provided that any two of R3, R4, R5, R6, R7 and R8 vicinal or geminal to one another together may form a ring;
when Q is phosphorous and Z is oxygen:
R1 and R2 are each independently hydrocarbyl, silyl, or substituted hydrocarbyl having an ES of about xe2x88x920.90 or less; R3 and R4 are each independently hydrogen, hydrocarbyl, a functional group, or substituted hydrocarbyl; R5 and R7 taken together form a double bond; R8 is not present; and R6 is xe2x80x94OR9, xe2x80x94NR1OR11, hydrocarbyl or substituted hydrocarbyl, wherein R9 is hydrocarbyl or substituted hydrocarbyl, and R10 and R11 are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl; and provided that any two of R3, R4, and R6 vicinal or geminal to one another may form a ring; or
R1 and R2 are each independently hydrocarbyl, silyl, or substituted hydrocarbyl having an ES of about xe2x88x920.90 or less; R3, R4, R5 and R6 are each independently hydrogen, hydrocarbyl, a functional group, or substituted hydrocarbyl; R7 is hydrocarbyl, silyl, or substituted hydrocarbyl; and R8 is not present; and provided that any two of R3, R4, R5, R6, and R7 vicinal or geminal to one another may form a ring;
when Q is nitrogen: R1 is hydrocarbyl, silyl, or substituted hydrocarbyl having an ES of about xe2x88x920.90 or less; R2 and R3 are each independently hydrogen, hydrocarbyl, a functional group, or substituted hydrocarbyl, or taken together form a double bond; R4 is hydrogen, hydrocarbyl, a functional group, or substituted hydrocarbyl; Z is oxygen; R6 and R7 taken together form a double bond; R8 is not present; R5 is xe2x80x94OR12, xe2x80x94R13 or xe2x80x94NR14R15, wherein R12 and R13 are each independently hydrocarbyl or substituted hydrocarbyl, and R14 and R15 are each hydrogen, hydrocarbyl or substituted hydrocarbyl; provided that when R2 and R3 taken together form an aromatic ring, R1 and R4 are not present; and further provided that any two of R2, R3, R4 and R5 vicinyl or germinal to one another together may form a ring.
A second aspect of the present invention concerns a xe2x80x9cfirstxe2x80x9d process for the polymerization of olefins, comprising the step of contacting, under polymerizing conditions, one or more polymerizable olefins with an active polymerization catalyst comprising the aforementioned transition metal complex.
A third aspect of this invention is a xe2x80x9csecondxe2x80x9d process for the manufacture of a polar copolymer by contacting, under polymerizing conditions, a hydrocarbon olefin, a polar olefin, and a polymerization catalyst comprising a nickel complex of a bidentate ligand which is an active ligand. This third aspect also includes an improved process for the manufacture of a polar copolymer by contacting, under polymerizing conditions, a hydrocarbon olefin, a polar olefin, and a polymerization catalyst comprising a nickel complex, wherein the improvement comprises that the polymerization catalyst comprises a nickel metal complex of a bidentate ligand which is an active ligand.
These and other features and advantages of the present invention will be more readily understood by those of ordinary skill in the art from a reading of the following detailed description. It is to be appreciated that certain features of the invention which are, for clarity, described below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination.
Herein, certain terms are used. Some of them are:
A xe2x80x9chydrocarbyl groupxe2x80x9d is a univalent group containing only carbon and hydrogen. If not otherwise stated, it is preferred that hydrocarbyl groups (and alkyl groups) herein contain 1 to about 30 carbon atoms.
By xe2x80x9csubstituted hydrocarbylxe2x80x9d herein is meant a hydrocarbyl group that contains one or more substituent groups which are inert under the process conditions to which the compound containing these groups is subjected (e.g., an inert functional group, see below). The substituent groups also do not substantially detrimentally interfere with the polymerization process or operation of the polymerization catalyst system. If not otherwise stated, it is preferred that substituted hydrocarbyl groups herein contain 1 to about 30 carbon atoms. Included in the meaning of xe2x80x9csubstitutedxe2x80x9d are chains or rings containing one or more heteroatoms, such as nitrogen, oxygen and/or sulfur, and the free valence of the substituted hydrocarbyl may be to the heteroatom. In a substituted hydrocarbyl, all of the hydrogens may be substituted, as in trifluoromethyl.
By xe2x80x9c(inert) functional groupxe2x80x9d herein is meant a group other than hydrocarbyl or substituted hydrocarbyl that is inert under the process conditions to which the compound containing the group is subjected. The functional groups also do not substantially interfere with any process described herein that the compound in which they are present may take part in. Examples of functional groups include halo (fluoro, chloro, bromo and iodo), and ether such as xe2x80x94OR22 wherein R22 is hydrocarbyl or substituted hydrocarbyl. In cases in which the functional group may be near a transition metal atom the functional group should not coordinate to the metal atom more strongly than the groups in those compounds are shown as coordinating to the metal atom, that is they should not displace the desired coordinating group.
By xe2x80x9csilylxe2x80x9d herein is meant a monovalent group whose free valence is to a silicon atom. The other three valencies of the silicon atom are bound to other groups such as alkyl, halo, alkoxy, etc. Silyl groups are also included in functional groups.
By a xe2x80x9ccocatalystxe2x80x9d or a xe2x80x9ccatalyst activatorxe2x80x9d is meant one or more compounds that react with a transition metal compound to form an activated catalyst species. One such catalyst activator is an xe2x80x9calkyl aluminum compoundxe2x80x9d which, herein, is meant a compound in which at least one alkyl group is bound to an aluminum atom. Other groups such as, for example, alkoxide, hydride and halogen may also be bound to aluminum atoms in the compound.
By xe2x80x9cneutral Lewis basexe2x80x9d is meant a compound, which is not an ion, which can act as a Lewis base. Examples of such compounds include ethers, amines, sulfides, olefins, and organic nitrites.
By xe2x80x9cneutral Lewis acidxe2x80x9d is meant a compound, which is not an ion, which can act as a Lewis acid. Examples of such compounds include boranes, alkylaluminum compounds, aluminum halides, and antimony [V] halides.
By xe2x80x9ccationic Lewis acidxe2x80x9d is meant a cation which can act as a Lewis acid. Examples of such cations are sodium and silver cations.
By an xe2x80x9cempty coordination sitexe2x80x9d is meant a potential coordination site on a transition metal atom that does not have a ligand bound to it. Thus if an olefin molecule (such as ethylene) is in the proximity of the empty coordination site, the olefin molecule may coordinate to the metal atom.
By a xe2x80x9cligand into which an olefin molecule may insert between the ligand and a metal atomxe2x80x9d, or a xe2x80x9cligand that may add to an olefinxe2x80x9d, is meant a ligand coordinated to a metal atom which forms a bond (Lxe2x80x94M) into which an olefin molecule (or a coordinated olefin molecule) may insert to start or continue a polymerization. For instance, with ethylene this may take the form of the reaction (wherein L is a ligand): 
By a xe2x80x9cligand which may be displaced by an olefinxe2x80x9d is meant a ligand coordinated to a transition metal which, when exposed to the olefin (such as ethylene), is displaced as the ligand by the olefin.
By a xe2x80x9cmonoanionic ligandxe2x80x9d is meant a ligand with one negative charge.
By a xe2x80x9cneutral ligandxe2x80x9d is meant a ligand that is not charged.
xe2x80x9cAlkyl groupxe2x80x9d and xe2x80x9csubstituted alkyl groupxe2x80x9d have their usual meaning (see above for substituted under substituted hydrocarbyl). Unless otherwise stated, alkyl groups and substituted alkyl groups preferably have 1 to about 30 carbon atoms.
By xe2x80x9carylxe2x80x9d is meant a monovalent aromatic group in which the free valence is to the carbon atom of an aromatic ring. An aryl may have one or more aromatic rings which may be fused, connected by single bonds or other groups.
By xe2x80x9csubstituted arylxe2x80x9d is meant a monovalent aromatic group substituted as set forth in the above definition of xe2x80x9csubstituted hydrocarbylxe2x80x9d. Similar to an aryl, a substituted aryl may have one or more aromatic rings which may be fused, connected by single bonds or other groups; however, when the substituted aryl has a heteroaromatic ring, the free valence in the substituted aryl group can be to a heteroatom (such as nitrogen) of the heteroaromatic ring instead of a carbon.
By xe2x80x9cRx and Ry taken together may form a double bondxe2x80x9d is meant a structure originally written as xe2x80x94CRRxxe2x80x94CRRyxe2x80x94 is, when Rx and Ry do in fact form a double bond, xe2x80x94CRxe2x95x90CRxe2x80x94. In this example each R is simply another group on a carbon atom to satisfy carbon""s normal valence requirement of 4.
By a xe2x80x9cxcfx80-allyl groupxe2x80x9d is meant a monoanionic ligand comprised of 1 sp3 and two sp2 carbon atoms bound to a metal center in a delocalized xcex73 fashion indicated by 
The three carbon atoms may be substituted with other hydrocarbyl groups or functional groups.
By xe2x80x9cESxe2x80x9d is meant a parameter to quantify steric effects of various groupings, see R. W. Taft, Jr., J. Am. Chem. Soc., vol. 74, p. 3120-3128 (1952), and M. S. Newman, Steric Effects in Organic Chemistry, John Wiley and Sons, New York, 1956, p. 598-603, which are both hereby included by reference. For the purposes herein, the ES values are those described for o-substituted benzoates in these publications. If the value of ES for a particular group is not known, it can be determined by methods described in these references.
By xe2x80x9cunder polymerization conditionsxe2x80x9d is meant the conditions for a polymerization that are usually used for the particular polymerization catalyst system being used. These conditions include things such as pressure, temperature, catalyst and cocatalyst (if present) concentrations, the type of process such as batch, semibatch, continuous, gas phase, solution or liquid slurry etc., except as modified by conditions specified or suggested herein. Conditions normally done or used with the particular polymerization catalyst system, such as the use of hydrogen for polymer molecular weight control, are also considered xe2x80x9cunder polymerization conditionsxe2x80x9d. Other polymerization conditions such as presence of hydrogen for molecular weight control, other polymerization catalysts, etc., are applicable with this polymerization process and may be found in the references cited herein.
By a xe2x80x9chydrocarbon olefinxe2x80x9d is meant an olefin containing only carbon and hydrogen.
By a xe2x80x9cpolar (co)monomerxe2x80x9d or xe2x80x9cpolar olefinxe2x80x9d is meant an olefin which contains elements other than carbon and hydrogen. When copolymerized into a polymer the polymer is termed a xe2x80x9cpolar copolymerxe2x80x9d. Useful polar comonomers are found in U.S. Pat. No. 5,866,663, WO 9905189, WO 9909078 and WO 9837110, and S. D. Ittel, et al., Chem. Rev., vol. 100, p. 1169-1203 (2000), all of which are incorporated by reference herein for all purposes as if fully set forth. Also included as a polar comonomer is CO (carbon monoxide).
For ease in describing the invention, the term xe2x80x9ctransition metalxe2x80x9d as used herein generally refers to Groups 3 through 11 of the periodic table (IUPAC) and the lanthamides, especially those in the 4th, 5th, 6th, and 10th periods. Suitable transition metals include Ni, Pd, Cu, Pt, Fe, Co, Ti, Zr, V, Hf, Cr, Ru, Rh and Re, with Ni, Fe, Ti, Zr, Cu and Pd being more preferred and Ni, Fe, Ti and Zr being especially preferred. Preferred oxiation states for some of the transition metals are Ni[II], Ti[IV], Zr[IV], and Pd[II].
The first polymerizations herein are carried out by a transition metal complex of (I).
Transition metal complexes in which (I) appears may, for example, have the formula (IV) 
wherein R1 through R8, Q and Z are as defined above; M1 is a transition metal; each X is independently a monoanion; and m is an integer equal to an oxidation state of M1.
Transition metal complexes in which (I) appears may, for example, also have the formula (IX) 
wherein R1 through R8, Q and Z are as defined above; M1 is a transition metal; L1 is a monoanionic ligand which may add to an olefin; n is equal to the oxidation state of M1 minus one; L2 is a ligand which may be displaced by an olefin or is an empty coordination site; or L1 and L2 taken together are a bidentate monoanionic ligand into which an olefin molecule may insert between the ligand and a metal atom; and W is a relatively noncoordinating anion.
In (I) and in all complexes and compounds containing (1), it is preferred that:
when Q is nitrogen:
R1 is (VII) (see below) or a 2,5-disubstituted pyrrole, more preferably (VII); and/or
R4 is alkyl, especially alkyl containing 1 to 6 carbon atoms, more preferably methyl; and/or
R5 is xe2x80x94OR12, xe2x80x94R13 or xe2x80x94NR14R15; and/or
R12 is alkyl, especially alkyl containing 1 to 6 carbon atoms; and/or
R13 is alkyl, especially alkyl containing 1 to 6 carbon atoms; and/or
R14 is alkyl containing 1 to 6 carbon atoms, especially methyl; and/or
R15 is hydrogen or alkyl; and/or
R15 and R4 taken together form a ring; and/or
R4 and R12 taken together form a ring; and/or
R4 and R13 taken together form a ring;
when Q is phosphorous and Z is nitrogen:
R1 and R2 are t-butyl; and/or
R8 is aryl or substituted aryl, especially (VII); and/or
R3, R4 and R5 are hydrogen, hydrocarbyl or substituted hydrocarbyl, especially hydrogen; and/or
R6 is aryl or substituted aryl, more preferably phenyl; and/or
R7 is benzyl;
when Q is phosphorous and Z is oxygen, and R5 and R7 taken together form a double bond:
R1 and R2 are t-butyl;
R3 and R4 are hydrogen; and/or
R6 is xe2x80x94OR9, xe2x80x94NR1OR11, alkyl, aryl or substituted aryl; and/or
R9 is alkyl or aryl, especially alkyl containing 1 to 6 carbon atoms or phenyl, and more preferably methyl; and/or
R10 and R11 are each independently aryl or substituted aryl, more preferably both phenyl; 
when Q is phosphorous and Z is oxygen, and R7 is hydrocarbyl or substituted hydrocarbyl:
R1 and R2 are t-butyl;
R3, R4, R5, and R6 are hydrogen; and or
R7 is aryl or substituted aryl.
In many of the above formulas a preferred aryl or substituted aryl group is (VII). 
In (VII) R20, R21, R22, R23 and R24 are each independently hydrogen, hydrocarbyl substituted hydrocarbyl or a functional group, provided than any two of R20, R21, R22, R23 and R24 ortho to another taken together may form a ring. Preferably one of R20 and R24 is not hydrogen, and more preferably both of R20 and R24 are not hydrogen. Useful groups for R20 and R24 include alkyl, especially alkyl containing 1 to 6 carbon atoms, halo especially chloro and bromo, alkoxy, aryl or substituted aryl especially phenyl. Individual useful groups (VII) include 2,6-diisopropylphenyl, 2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2,6-dimethyl-4-chlorophenyl, and 2,6-dimethyl-4-bromophenyl.
Ligands (I) in which Q is nitrogen may be made by the reaction of a pyruvic (or a pyruvic-like compound which contains a group to be R4 that is something other than methyl) acid ester or amide, or an xcex1,xcex2-dione and an appropriate arylamine. Ligands (I) in which Q is phosphorous and Z is nitrogen may be prepared by the reaction of an appropriate imine with (di-t-butylphosphino)methyl lithium, with subsequent reaction of the lithium amide formed with a halocarbon such as benzyl bromide.
Transition metal complexes having neutral ligands such as (IV) and (IX) can be made by a variety of methods, see for instance previously incorporated U.S. Pat. No. 5,880,241. In part how such compounds are made depends upon the transition metal compound used in the synthesis of the complex and in what each X (anion) in the final product is. For example, for transition metals such as Ni[II], Fe[II], Co[II], Ti[IV] and Zr[IV] a metal halide such as the chloride may be mixed with the neutral ligand and transition metal complex, wherein X is halide. When it is desired that one of X be a relatively noncoordinating anion and another X is an anion which may add across an olefinic bond (as in ethylene), for example using a nickel compound, then nickel allyl chloride dimer may be mixed with a neutral ligand in the presence of an alkali metal salt of a relatively noncoordinating anion such as sodium tetrakis[3,5-bistrifluoromethylphenyl]borate (BAF for the anion alone) to form a complex in which one X is xcfx80-allyl and the other anion BAF.
For the transition metal complexes in which (I) (a neutral ligand) is present preferred transition metals are Pd, Ni, Fe, Co, Ti, Zr, Hf, Sc, V, Cr, and Ru, and especially preferred transition metals are Pd, Ni, Ti, Zr, Fe and Co, and a more preferred transition metals are Ni, Fe, Ti and Zr.
In the first process useful olefins include an olefin of the formula H2Cxe2x95x90CH(CH2)nG (VIII), where n is 0 or an integer of 1 or more, g is hydrogen, xe2x80x94CO2R25 or xe2x80x94C(O)NR252, and each R25 is independently hydrogen, or hydrocarbyl substituted hydrocarbyl, styrenes, norbornenes and cyclopentenes. Preferred olefins are when g is hydrogen and n is 0 (ethylene); or g is hydrogen and n is an integer of 1 to 12, especially one (propylene); or g is xe2x80x94CO2R25 wherein R25 is alkyl, especially alkyl containing 1 to 6 carbon atoms and more preferably methyl; and when g is xe2x80x94CO2R25, and n is 0 or an integer of 2 to 12. Copolymers may also be prepared. A preferred copolymer is one containing ethylene and one or more others of (VIII), for example the copolymers ethylene/1-hexene, ethylene/propylene, ethylene/methyl acrylate (n is 0 and R25 is methyl), and ethylene/methyl- or ethyl-1-undecylenate.
In (IX) when an olefin may insert between L1 and the transition metal atom, and L2 is an empty coordination site or is a ligand which may be displaced by an olefin, or L1 and L2 taken together are a bidentate monoanionic ligand into which an olefin may inserted between that ligand and the transition metal atom, (IX) may by itself catalyze the polymerization of an olefin. Examples of L1 which form a bond with the metal into which an olefin may insert between it and the transition metal atom are hydrocarbyl and substituted hydrocarbyl, especially phenyl and alkyl, and particularly methyl, hydride, and acyl; and ligands L2 which ethylene may displace include phosphine such as triphenylphosphine, nitrile such as acetonitrile, ether such as ethyl ether, pyridine, and tertiary alkylamines such as TMEDA (N,N,Nxe2x80x2,Nxe2x80x2-tetramethylethylenediamine). Ligands in which L1 and L2 taken together are a bidentate monoanionic ligand into which an olefin may insert between that ligand and the transition metal atom include xcfx80-allyl- or xcfx80-benzyl-type ligands (in this instance, sometimes it may be necessary to add a neutral Lewis acid cocatalyst such as triphenylborane to initiate the polymerization, see for instance previously incorporated U.S. Pat. No. 5,880,241). For a summary of which ligands ethylene may insert into (between the ligand and transition metal atom) see for instance J. P. Collman, et al., Principles and Applications of Organotransition Metal Chemistry, University Science Books, Mill Valley, Calif., 1987.
If for instance L1 is not a ligand into which ethylene may insert between it and the transition metal atom or if (IV) is present, it may be possible to add a cocatalyst which may convert L1 or X into a ligand which will undergo such an insertion. Thus if L1 or X is halide such as chloride or bromide, or carboxylate, it may be converted to hydrocarbyl such as alkyl by use of a suitable alkylating agent such as an alkylaluminum compound, a Grignard reagent or an alkyllithium compound. It may be converted to hydride by using of a compound such as sodium borohydride. It is preferred that when the transition metal is alkylated or hydrided, that a relatively noncoordinating anion is formed. Such reactions are described in previously incorporated U.S. Pat. No. 5,880,241.
A preferred cocatalyst in the first process is an alkylaluminum compound, and useful alkylaluminum compounds include trialkylaluminum compounds such as triethylaluminum, trimethylaluminum and tri-1-butylaluminum, alkyl aluminum halides such as diethylaluminum chloride and ethylaluminum dichloride, and aluminoxanes such as methylaluminoxane.
In another preferred form L1 and L2 taken together may be a xcfx80-allyl or xcfx80-benzyl group such as 
wherein R is hydrocarbyl, and xcfx80-allyl and xcfx80-benzyl groups are preferred. When L1 and L2 taken together are xcfx80-allyl or xcfx80-benzyl, in order to initiate the polymerization it may be useful to have a Lewis acid such as triphenylboron or tris(pentafluorophenyl)boron also present.
In the first polymerization process herein, the temperature at which the polymerization is carried out is about xe2x88x92100xc2x0 C. to about +200xc2x0 C., preferably about xe2x88x9260xc2x0 C. to about 170xc2x0 C., more preferably about xe2x88x9220xc2x0 C. to about 140xc2x0 C. The pressure of the ethylene or other gaseous olefin at which the polymerization is carried out is not critical, atmospheric pressure to about 275 MPa being a suitable range.
The first polymerization process herein may be run in the presence of various liquids, particularly aprotic organic liquids. The catalyst system, ethylene or other olefinic monomer, and/or polymer may be soluble or insoluble in these liquids, but obviously these liquids should not prevent the polymerization from occurring. Suitable liquids include alkanes, cycloalkanes, selected halogenated hydrocarbons, and aromatic hydrocarbons. Specific useful solvents include hexane, toluene, benzene, methylene chloride, 1,2,4-trichlorobenzene and p-xylene.
The first polymerization process herein may also initially be carried out in the xe2x80x9csolid statexe2x80x9d by, for instance, supporting the transition metal compound on a substrate such as silica or alumina, activating if necessary it with one or more cocatalysts and contacting it with, say, ethylene. Alternatively, the support may first be contacted (reacted) with a cocatalysts (if needed) such as an alkylaluminum compound, and then contacted with an appropriate transition metal compound. The support may also be able to take the place of a Lewis or Bronsted acid, for instance an acidic clay such as montmorillonite, if needed. These xe2x80x9cheterogeneousxe2x80x9d catalysts may be used to catalyze polymerization in the gas phase or the liquid phase. By gas phase is meant that a gaseous olefin is transported to contact with the catalyst particle. In a preferred form of gas phase polymerization the polymerization catalysts and/or polymer formed is in the form of a fluidized bed.
In all of the polymerization processes described herein olefinic oligomers and polymers are made. They may range in molecular weight from oligomeric POs (polyolefins), to lower molecular weight oils and waxes, to higher molecular weight POs. One preferred product is a POs with a degree of polymerization (DP) of about 10 or more, preferably about 40 or more. By xe2x80x9cDPxe2x80x9d is meant the average number of repeat units in a PO molecule.
Depending on their properties, the POs made by the processes described herein are useful in many ways. For instance if they are thermoplastics, they may be used as molding resins, for extrusion, films, etc. If they are elastomeric, they may be used as elastomers. If they contain functionalized monomers such as acrylate esters or other polar monomers, they are useful for other purposes, see for instance previously incorporated U.S. Pat. No. 5,880,241.
Depending on the first process conditions used and the polymerization catalyst system chosen, the POs may have varying properties. Some of the properties that may change are molecular weight and molecular weight distribution, crystallinity, melting point, and glass transition temperature. Except for molecular weight and molecular weight distribution, branching can affect all the other properties mentioned, and branching may be varied (using the same nickel compound) using methods described in previously incorporated U.S. Pat. No. 5,880,241.
It is known that blends of distinct polymers, that vary for instance in the properties listed above, may have advantageous properties compared to xe2x80x9csinglexe2x80x9d polymers. For instance it is known that polymers with broad or bimodal molecular weight distributions may be melt processed (be shaped) more easily than narrower molecular weight distribution polymers. Thermoplastics such as crystalline polymers may often be toughened by blending with elastomeric polymers.
Therefore, methods of producing polymers which inherently produce polymer blends are useful especially if a later separate (and expensive) polymer mixing step can be avoided. However in such polymerizations one should be aware that two different catalysts may interfere with one another, or interact in such a way as to give a single polymer.
In such a process the transition metal containing polymerization catalyst disclosed herein can be termed the first active polymerization catalyst. A second active polymerization catalyst (and optionally one or more others) is used in conjunction with the first active polymerization catalyst. The second active polymerization catalyst may be another late transition metal catalyst, for example as described in previously incorporated U.S. Pat. No. 5,880,241, U.S. Pat. No. 6,060,569 and U.S. Pat. No. 6,174,795, as well as U.S. Pat. No. 5,714,556 and U.S. Pat. No. 5,955,555 which are also incorporated by reference herein as if fully set forth.
Other useful types of catalysts may also be used for the second active polymerization catalyst. For instance so-called Ziegler-Natta and/or metallocene-type catalysts may also be used. These types of catalysts are well known in the polyolefin field, see for instance Angew. Chem., Int Ed. Engl., vol. 34, p. 1143-1170 (1995), EP-A-0416815 and U.S. Pat. No. 5,198,401 for information about metallocene-type catalysts, and J. Boor Jr., Ziegler-Natta Catalysts and Polymerizations, Academic Press, New York, 1979 for information about Ziegler-Natta-type catalysts, all of which are hereby included by reference. Many of the useful polymerization conditions for all of these types of catalysts and the first active polymerization catalysts coincide, so conditions for the polymerizations with first and second active polymerization catalysts are easily accessible. Oftentimes the xe2x80x9cco-catalystxe2x80x9d or xe2x80x9cactivatorxe2x80x9d is needed for metallocene or Ziegler-Natta-type polymerizations. In many instances the same compound, such as an alkylaluminum compound, may be used as an xe2x80x9cactivatorxe2x80x9d for some or all of these various polymerization catalysts.
In one preferred process described herein the first olefin(s) (olefin(s) polymerized by the first active polymerization catalyst) and second olefin(s) (the monomer(s) polymerized by the second active polymerization catalyst) are identical. The second olefin may also be a single olefin or a mixture of olefins to make a copolymer.
In some processes herein the first active polymerization catalyst polymerizes one or olefins, a monomer that may not be polymerized by said second active polymerization catalyst, and/or vice versa. In that instance two chemically distinct polymers may be produced. In another scenario two monomers would be present, with one polymerization catalyst producing a copolymer, and the other polymerization catalyst producing a homopolymer.
Likewise, conditions for such polymerizations, using catalysts of the second active polymerization type, will also be found in the appropriate above mentioned references.
Two chemically different active polymerization catalysts are used in this polymerization process. The first active polymerization catalyst is described in detail above. The second active polymerization catalyst may also meet the limitations of the first active polymerization catalyst, but must be chemically distinct. For instance, it may utilize a different ligand which differs in structure between the first and second active polymerization catalysts. In one preferred process, the ligand type and the metal are the same, but the ligands differ in their substituents.
Included within the definition of two active polymerization catalysts are systems in which a single polymerization catalyst is added together with another ligand, preferably the same type of ligand, which can displace the original ligand coordinated to the metal of the original active polymerization catalyst, to produce in situ two different polymerization catalysts.
The molar ratio of the first active polymerization catalyst to the second active polymerization catalyst used will depend on the ratio of polymer from each catalyst desired, and the relative rate of polymerization of each catalyst under the process conditions. For instance, if one wanted to prepare a xe2x80x9ctoughenedxe2x80x9d thermoplastic polyethylene that contained 80% crystalline polyethylene and 20% rubbery polyethylene, and the rates of polymerization of the two catalysts were equal, then one would use a 4:1 molar ratio of the catalyst that gave crystalline polyethylene to the catalyst that gave rubbery polyethylene. More than two active polymerization catalysts may also be used if the desired product is to contain more than two different types of polymer.
The polymers made by the first active polymerization catalyst and the second active polymerization catalyst may be made in sequence, i.e., a polymerization with one (either first or second) of the catalysts followed by a polymerization with the other catalyst, as by using two polymerization vessels in series. However it is preferred to carry out the polymerization using the first and second active polymerization catalysts in the same vessel(s), i.e., simultaneously. This is possible because in most instances the first and second active polymerization catalysts are compatible with each other, and they produce their distinctive polymers in the other catalyst""s presence. Any of the processes applicable to the individual catalysts may be used in this polymerization process with 2 or more catalysts, i.e., gas phase, liquid phase, continuous, etc.
The polymers produced by this process may vary in molecular weight and/or molecular weight distribution and/or melting point and/or level of crystallinity, and/or glass transition temperature and/or other factors. The polymers produced are useful as molding and extrusion resins and in films as for packaging. They may have advantages such as improved melt processing, toughness and improved low temperature properties.
Catalyst components which include transition metal complexes of (I), with or without other materials such as one or more cocatalysts and/or other polymerization catalysts are also disclosed herein. For example, such a catalyst component could include the transition metal complex supported on a support such as alumina, silica, a polymer, magnesium chloride, sodium chloride, etc., with or without other components being present. It may simply be a solution of the transition metal complex, or a slurry of the transition metal complex in a liquid, with or without a support being present.
Hydrogen or other chain transfer agents such as silanes (for example trimethylsilane or triethylsilane) may be used to lower the molecular weight of polyolefin produced in the polymerization process herein. It is preferred that the amount of hydrogen present be about 0.01 to about 50 mole percent of the olefin present, preferably about 1 to about 20 mole percent. The relative concentrations of a gaseous olefin such as ethylene and hydrogen may be regulated by varying their partial pressures.
In the second polymerization process herein, a transition metal complex of Groups 6 to 11, preferably Groups 8-11, more preferably Ni or Pd, and especially preferably Ni, is used. The transition metal is complexed to an xe2x80x9cactive ligandxe2x80x9d, and this ligand is bi- or higher (tri-, tetra, etc.) dentate. The ligand may be neutral (have no charge) or anionic (have one or more negative charges). Bidentate ligands are preferred. Besides having this denticity, the active ligand has certain properties, measured by a specific test, that classify it as an active ligand. The ligand may be active with one transition metal but not with another. The complex for any given ligand with each transition metal should be separately tested (see below).
When most such transition metal complexes are used as olefin polymerization catalyst (components), they are usually used in conjunction with other catalyst components, such as alkylating agents, and/or Lewis acids, and/or others. It has been found that these transition metal complexes, when having at least one xcfx80-allyl also coordinated to the transition metal, will initiate the polymerization of ethylene, and/or copolymerization of ethylene and ethyl-10-undecylenate, under specified conditions (see below) in the absence of any other cocatalysts. This in a sense makes them especially active in olefin polymerizations, especially polymerizations in which a polar monomer is used (and copolymerized) with a hydrocarbon olefin, especially ethylene.
Generally speaking, these ligands have at least two different types of groups which coordinate to the transition metal, for example two different heteroatom groups such as (in a bidentate ligand) N and O, or N and P, or P and O, etc. In some instances, both the heteroatoms and the groups of which they are a part may be the same. In some instances, the heteroatoms may be same, but the groups of which they are a part are different, for example for nitrogen they may be amino or imino, for oxygen they may be keto or hydroxy, etc. Many of these ligands happen to be so-called xe2x80x9chemilabilexe2x80x9d or xe2x80x9chybridxe2x80x9d ligands, although the fact that a ligand is hemilabile or hybrid does not guarantee it will be an active ligand, and vice versa. Hemilabile and hybrid ligands are known in the art, see for instance: J. C. Jeffrey et al., Inorg. Chem., vol. 18, p. 2658 (1979); L. P. Barthel-Rosa, et al., Inorg. Chem., vol. 37, p. 633 (1998); S. Mecking, et al., Organometallics vol. 15, p. 2650 (1996); A. M. Aligeier, et al., Organometallics, vol. 13, p. 2928 (1994); M. Nandi, M., et al., J. Am. Chem. Soc., vol. 121, p. 9899 (1999); P. Braunstein, et al., Organometallics, vol. 15, p. 5551 (1996); A. Bader, et al., Coord. Chem. Rev., vol. 108, p. 27-100 (1991); C. Slone, et al., In Progress in Inorganic Chemistry, K. D. Karlin, Ed.; John Wiley and Sons, New York (1999), p. 233-350, all of which are hereby included by reference. Although none of these guides is absolute, they do suggest to the artisan what ligands may be active ligands. Making the transition metal complex and testing it by the simple method described below allows a determination whether the ligand is an active ligand.
When using active ligand complexes to form polar copolymers, preferred hydrocarbon olefins are ethylene and H2Cxe2x95x90CHR26, wherein R26 is hydrogen, alkyl or substituted alkyl, preferably hydrogen or n-alkyl, and ethylene is especially preferred. A preferred polar olefin is H2Cxe2x95x90CHR27CO2R28, particularly wherein R27 is alkylene or a covalent bond, more preferably n-alkylene or a covalent bond, and especially preferably a covalent bond, and R28 is hydrocarbyl, substituted hydrocarbyl, or a metal, or any easily derivable functionality such as amide or nitrile, and more preferably R28 is hydrocarbyl and substituted hydrocarbyl. Another type of preferred polar olefin is a vinyl olefin wherein the polar group is attached directly to a vinylic carbon atom, for example when R27 is a covalent bond. CO may also be used as a polar olefin; however, when CO is present it is preferred that at least one other polar olefin is also present.
In the second process, especially when ethylene is the hydrocarbon olefin, it is preferred that the polymerization process be run at a temperature of about 50xc2x0 C., more preferably 60xc2x0 C. to about 170xc2x0 C., and an ethylene partial pressure of at least about 700 kPa. More preferably the temperature range is about 80xc2x0 C. to about 140xc2x0 C. and/or a lower ethylene pressure is about 5.0 MPa or more, and/or a preferred upper limit on ethylene pressure is about 200 MPa, especially preferably about 20 MPa. The polymerizations may otherwise be carried out in the xe2x80x9cnormalxe2x80x9d manner for such ligands (including the presence of Lewis acids, which are not present in part of the test to determine whether a ligand is an active ligand.
Polymerization without added Lewis acids is described herein in Examples 39-45, 54-58, 70, 73, 91 and 192. Examples of ligands with excellent potential for being active ligands are listed in previously incorporated S. Ittel, et al., Chem. Rev., vol. 100, p. 1177-1179 and are (Reference Numbers from their Table 2 given): 116 E-33; 116 E-32; 116 E-15; 116 E-57; 116 E-51; 116 E-60; 116 E-185; 116 E-23; 116 E-89; 116 E-29; 116 E-27; 116 E-61; 116 E-43; 116 E-49; 116 E-39; 116 E-56; 116 E-36; 116 E-95; 116 E-3; 116 E-184; 116 E-141; 116 E-144; 116 E-53; 116 E-105; 116 E-106; 116 E-37; 116 E-46; 116 E-44; 139; 116 E-10; 116 E-162; 116 E-16; 116 E-48; 116 E-30; 116 E-47; 116 E-55; 116 E-24; 116 E-54; 140; 136; 116 E-34; and 116 E-160. From Table 8, p. 1195, 416. Under certain circumstances xcex1-diimines are not preferred neutral active ligands, and/or salicylaldimines are not preferred monoanionic active ligands.
Herein, a ligand is termed an xe2x80x9cactive ligandxe2x80x9d if it meets one or both of the following two tests:
Test 1
The yield of polyethylene obtained under condition 1xe2x80x941 is greater than or equal to one half of the maximum yield of polyethylene obtained under conditions 1-2 and 1-3.
Conditions 1xe2x80x941
Heat a clean 600 mL Parr(copyright) reactor under vacuum, and then allow it to cool under nitrogen. Next, heat the reactor to 80xc2x0 C. In a nitrogen-filled drybox, weigh out 0.0085 mmole of the neutral nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)], the cationic nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)]+[B(3,5-(CF3)2C6H3)4]xe2x88x92, or the cationic nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)]+[B(C6F5)4]xe2x88x92 and dissolve it in 60 mL of chlorobenzene and then place the solution in a 150 mL addition cylinder. Seal the cylinder and bring it out of the drybox and attach it to the Parr(copyright) reactor. Utilize 2.1 MPa of nitrogen to force the solution in the addition cylinder into the 80xc2x0 C. reactor. Quickly vent the nitrogen and fill the reactor with ethylene to 6.9 MPa. Stir the reaction mixture at 600 rpm while adjusting the temperature of the reaction mixture to 100xc2x0 C. Maintain the temperature at 100xc2x0 C. and the pressure at 6.9 MPa while continuing to stir for a total of 1 h. Remove the heat source and vent the ethylene. Back-fill with 0.7 MPa nitrogen and vent the nitrogen after brief stirring. Repeat this two more times. Pour the room temperature mixture into 500 mL methanol, filter, and wash with methanol. Blend the resulting polymer with methanol, filter, and wash with methanol. Repeat this blending/washing procedure two more times, and dry the polymer in vacuo overnight.
Condition 1-2
Repeat the procedure of Condition 1xe2x80x941, except include 10 equiv of BPh3 in the addition funnel.
Condition 1-3
Repeat the procedure of Condition 1xe2x80x941, except include 10 equiv of B(C6F5)3 in the addition funnel.
Test 2
The yield of E/E-10-U copolymer obtained under Condition 1-4 is greater than or equal to one third of the maximum yield of polyethylene obtained under Conditions 1-5 and 1-6.
Condition 1-4
Heat a clean 600 mL Parr(copyright) reactor under vacuum, and then allow it to cool under nitrogen. In a nitrogen-filled drybox, weigh out 0.0094 mmole of the neutral nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)], the cationic nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)]+[B(3,5-(CF3)2C6H3)4]xe2x88x92, or the cationic nickel(II) allyl complex [(L{circumflex over ( )}Lxe2x80x2)Ni(C3H5)]+[B(C6F5)4]xe2x88x92 and dissolve it in 90 mL of toluene and 60 mL of E-10-U in a 300 mL RB flask. Seal the flask with a rubber septum and bring it out of the drybox and transfer the solution into the autoclave via a cannula under positive nitrogen pressure. Seal the autoclave and pressure it to 0.7 MPa nitrogen. Then release the nitrogen. Repeat this pressurizing/venting procedure two more times. Add about 0.03 MPa of nitrogen to the autoclave and then stir the reaction mixture at 600 rpm. Next, apply 4.5 MPa of ethylene pressure. Quickly place the autoclave in a preheated 100xc2x0 C. oil bath. Adjust the pressure of the autoclave to 5.5 MPa. Maintain the temperature at 100xc2x0 C. and the pressure at 5.5 MPa while continuing to stir for a total of 2 h. Remove the heat source and vent the ethylene. Back-fill with 0.7 MPa nitrogen and vent the nitrogen after brief stirring. Repeat this two more times. Pour the room temperature mixture into 500 mL methanol, filter, and wash with methanol. Blend the resulting polymer with methanol, filter, and wash with methanol. Repeat this blending/washing procedure two more times, and dry the polymer in vacuo overnight.
Condition 1-5
Repeat the procedure of Conditions 1-4, except include 80 equiv of BPh3 in the RB flask.
Condition 1-6
Repeat the procedure of Conditions 14, except include 80 equiv of B(C6F5)3 in the RB flask. 
In the tests above for xe2x80x9cactive Ligandsxe2x80x9d L{circumflex over ( )}Lxe2x80x2 is bidentate ligand being tested, and E-10-U is ethyl 10-undecylenate. Preferred active ligands are those that meet the conditions for Test 2.
In the Examples except where noted, all pressures are gauge pressures. In the Examples, the following abbreviations are used:
Amxe2x80x94amyl
Arxe2x80x94aryl
BAFxe2x80x94B(3,5-C6H3xe2x80x94(CF3)2)4xe2x88x92
BArFxe2x80x94B(C6F5)4xe2x88x92
BHTxe2x80x942,6-di-t-butyl-4-methylphenol
BQxe2x80x941,4-benzoquinone
Buxe2x80x94butyl
Bu2Oxe2x80x94dibutyl ether
CBxe2x80x94chlorobenzene
Cmpdxe2x80x94compound
Cyxe2x80x94cyclohexyl
DSCxe2x80x94Differential Scanning Calorimetry
Exe2x80x94ethylene
E-10-Uxe2x80x94ethyl-10-undecylenate
EGxe2x80x94end-group, refers to the ester group of the acrylate being located in an unsaturated end group of the ethylene copolymer
EGPEAxe2x80x942-phenoxyethyl acrylate
Eocxe2x80x94end-of-chain
Equivxe2x80x94equivalent
Etxe2x80x94ethyl
Et2Oxe2x80x94diethyl ether
GPCxe2x80x94gel permeation chromatography
HAxe2x80x94hexyl acrylate
Hexxe2x80x94hexyl
ICxe2x80x94in-chain, refers to the ester group of the acrylate being bound to the main-chain of the ethylene copolymer
Incorpxe2x80x94incorporation
i-Prxe2x80x94isopropyl
LAxe2x80x94Lewis acid
LDAxe2x80x94lithium N,N-diethylamide
M.W.xe2x80x94molecular weight
MAxe2x80x94methyl acrylate
Mexe2x80x94methyl
MeOHxe2x80x94methanol
MIxe2x80x94melt index
Mnxe2x80x94number average molecular weight
Mpxe2x80x94peak molecular weight (by GPC)
Mwxe2x80x94weight average molecular weight
Ndxe2x80x94not determined
PDIxe2x80x94Mw/Mn
PExe2x80x94polyethylene
Phxe2x80x94phenyl
PMAO-IPxe2x80x94poly(methylaluminoxane) available from Akzo-Nobel, Inc.
PPAxe2x80x942,2,3,3,3-pentafluoropropyl acrylate
Pressxe2x80x94pressure
RBxe2x80x94round-bottomed
RIxe2x80x94refractive index
RT or Rtxe2x80x94room temperature
t-Buxe2x80x94t-butyl
TCBxe2x80x941,2,4-trichlorobenzene
Temp: Temperature
THAxe2x80x943,5,5-trimethylhexyl acrylate
THFxe2x80x94tetrahydrofuran
TLCxe2x80x94thin layer chromatography
TONxe2x80x94turnovers, moles of olefinic compound polymerized/mole of transition metal compound
Total Mexe2x80x94total number of methyl groups per 1000 methylene groups as determined by 1H or 13C NMR analysis
UVxe2x80x94ultraviolet
All the operations related to the catalyst (transition metal compound) synthesis were performed in a nitrogen drybox or using a Schlenk line with nitrogen protection. Anhydrous solvents were used. Solvents were distilled from drying agents under nitrogen using standard procedures: tetrahydrofuran (THF), from sodium benzophenone ketyl. Ni(II) allyl chloride (or bromide) was prepared according to the literature.
(t-Butyl)2PCH2Li was synthesized by reacting (t-butyl)2PCH3 with t-butyl lithium in heptane in a 109xc2x0 C. bath for 4 d. The product was filtered and washed with pentane. (t-Butyl)2PLi was synthesized by reacting (t-butyl)2PH with n-butyl lithium in heptane at 90xc2x0 C. for 6 h.
The 1H, 13C and 31P NMR spectra were recorded using a Bruker 500 MHz spectrometer.
Total methyls per 1000 CH2 are measured using different NMR resonances in 1H and 13C NMR spectra. Because of accidental overlaps of peaks and different methods of correcting the calculations, the values measured by 1H and 13C NMR spectroscopy will not be exactly the same, but they will be close, normally within 10-20% at low levels of acrylate comonomer. In 13C NMR spectra, the total methyls per 1000 CH2 are the sums of the 1B1, 1B2, 1B3, and 1B4+, EOC resonances per 1000 CH2, where the CH2xe2x80x2s do not include the CH2xe2x80x2s in the alcohol portions of the ester group. The total methyls measured by 13C NMR spectroscopy do not include the minor amounts of methyls from the methyl vinyl ends nor the methyls in the alcohol portion of the ester group. In 1H NMR spectra, the total methyls are measured from the integration of the resonances from 0.6 to 1.08 ppm and the CH2xe2x80x2s are determined from the integral of the region from 1.08 to 2.49 ppm. It is assumed that there is 1 methine for every methyl group, and ⅓ of the methyl integral is subtracted from the methylene integral to remove the methine contribution. The methyl and methylene integrals are also usually corrected to exclude the values of the methyls and methylenes in the alcohol portion of the ester group, if this is practical. Because of the low levels of incorporation, this is usually a minor correction. Corrections are also made to exclude any contributions from acrylate homopolymer to the methyl or methylene integrals in both the 13C and 1H spectra where this is warranted.
In the Examples the following ligands and transition metal compounds are made by the general indicated methods. Ligand and transition metal compound numbers are shown in the various synthetic equations. 